<p>&nbsp;Observing taxidermied birds&#39; traits, Darwin found that there are correlation between their&nbsp;specific traits and their habitats. He&nbsp;had inspiration from Hippocrates&#39;s view on the topic, which made&nbsp;Darwin establish and&nbsp;publish&nbsp;his view with &quot;pangenesis&quot;.&nbsp;Pangenesis is was Darwin&#39;s model to explain the mechanism for heredity and evolution using imagined particles named as gemmulewhich&nbsp;appeared in his book&nbsp;&#39;The Variation of Animals and Plants under Domestication&#39;, pubilshed in 1868, nine years after pubilcation of his famous book &#39;On the Origin of Species&#39;.&nbsp;</p>

<p>&nbsp;Gemmules were assumed to be spread within all parts of body and carried in the bloodstream to the reproductive organs where they accumulated in germ line cells. Gemmules were also able to be changed easily affected by surroundings or natural pressures. It seemed to explain well how acquired traits are inhereted, yet there were lots of problems preventing it accepted.</p>